The present invention relates to output transformer for wound-rotor high tension of plural output type to be used in inverters for driving loads such as cold cathode fluorescent lamps and the like and power source device using said wound-rotor output transformers for high tension.
Heretofore, a transformer (for example, refer to Japanese official gazette, Japanese Patent Kokai 2002-07575) is known wherein a plurality of mid leg portion and separate wall portion and external wall portion are formed at least one part of a set of cores forming a closed magnetic circuit, and separate secondary windings are mounted concentrically on each of the mid leg portion, and a primary winding is mounted on the inside of the outer peripheral wall portion to enclose the whole secondary windings thereby exciting the plural secondary windings simultaneously by one primary winding.
Furthermore, as illustrated in FIG. 16, in case of driving cold cathode fluorescent lamp 46 with output of the wound-rotor transformer, heretofore, an electrode of the fluorescent lamp 46 is connected to a high tension terminal of the winding of the secondary side of a wound-rotor transformer T by means of a capacitor, and the capacitor and the other electrode of the fluorescent lamp 46 is connected to the earth by means of a resistor. Furthermore, in case of driving four pieces of the fluorescent lamps, as shown in FIG. 17, wound-rotor transformers T1, T2, T3 and T4 are prepared, and two pieces of the fluorescent lamps 46, 46 are connected in series, and among each pair of the fluorescent lamps, the fluorescent lamps 46, 46 of one part are connected to the secondary side high tension terminals of the corresponding wound-rotor transformers T1, T3 by means of a ballast capacitor, and the other part of the fluorescent lamps 44, 44 are connected to the secondary side high tension terminals of the corresponding wound-rotor transformers T2, T3 by means of a ballast capacitor, and the other terminals at the secondary side of each wound-rotor transformers T1, T2, T3, T4 is connected to the earth.
Furthermore, in ballastless discharge lamp lighting circuit using multilamp leakage transformers, a DC/AC inverter circuit (for example, refer to official gazette of Japanese Patent Kokai 2002-075756) is known in which both terminals of one part of the secondary winding are connected to both terminals of the discharge lamp by means of an earth wire, and the other secondary windings are connected to both terminals of another discharge lamp by means of the earth wire, and as a result, two discharge lamps are simultaneously driven by one input.
Heretofore, in the wound-rotor output transformers for high tension, and in case of constructing a plurality of output units at the secondary side, there has been problems that structure of the core and arrangement of windings become complicated and large size structure.
An object of the present invention is to solve the foregoing problems.
Furthermore, in a system of driving fluorescent lamps by connecting one electrode of the fluorescent lamp (discharge lamp) to a high tension terminal at the secondary side of the wound-rotor transformer and connecting the other electrode to the earth wire, one terminal side of the fluorecent lamp becomes high tension, and the other terminal side becomes low tension thereby the transformer connected side turns to bright while the earth wire connected side turns to dark, and irregularity of luminance occurs which are points of problems. In a system of driving two pieces of fluorescent lamps with two pieces of wound-rotor transformers, high tension occurs at both terminals of two pieces of the fluorescent lamps, and thus, occurrence of generation of irregularity of brightness may be eliminated but a wound-rotor transformer is required for each of the fluorescent lamps which does not meet with miniaturization of the wound-rotor transformers which are points of problems.
The present invention aims to solve the foregoing problems.